In this research, long-term measurement of inside and surface temperature of DSF is implemented and analyzed on the thermal performance of the system to provide validation data in the future researches. Interior air temperature rises while it go through double skin system and this is enforced by the amount of solar radiation. However, the temperature at fourth and fifth floor is almost similar due to air flow hindrance by small outlet area. The surface temperatures at the inside of outer glazing, inner glazing, and exterior wall show that double skin system is beneficial at heating season by raising surface temperatures regardless of solar radiation amount. Currently, the building is receiving additional high summer cooling load especially at 4th and 5th floor by staggered hot air at the top of the double skin system.